Messrs. Cabrera and Montiel, the domestic courts examined both the medical certificates and the expert opinions in order to assess the allegations of torture, the Court fins that this proceeding had a purpose other than to investigate the alleged perpetrators of these allegations since, at the same time, Messrs. Cabrera and Montiel were being tried. Therefore, the fact that no independent investigation against the alleged perpetrators was conducted by the ordinary courts prevented any attempt to dispel or clarify the allegations of torture. Based on the foregoing, it is clear to this Court that the State failed in its duty to investigate ex officio the human rights violations committed against Messrs. Cabrera and Montiel. In the instant case, it was essential that the different domestic courts order new procedures to investigate the link between the signs found on the victims’ bodies and the acts allegedly suffered as torture. 132. The Court also considers that this obligation to investigate the alleged acts of torture was even more crucial bearing in mind the prior context of the instant case, as regards the confessions and statements made under duress and the duty of strict due diligence that should apply in areas with a heavy military presence (supra paras. 86 to 89). In this respect, the United Nations Special Rapporteur on Torture has pointed out that “generally speaking, not only judges but also lawyers, the Public Prosecutor's Office and the judicial police itself are overwhelmed with work, which may result in a tendency to rely on confessions as a way of resolving cases rapidly.” 197 Moreover, the United Nations Special Rapporteur held that “[…] in normal practice, there is broad discretion in the application of the law and therefore there is a great risk that investigations may be falsified, carried out under duress or recorded illegally, ignoring potentially key evidence or considering other less important evidence that might slant the investigation in such a way as to affect or benefit someone; evidence may even be made intentionally to "disappear.” 198 3. Legal classification 133. The Court has indicated that the violation of person’s right to physical and psychological integrity is a category of violation that has several gradations. It encompasses actions ranging from torture to other types of humiliation or cruel, inhuman or degrading treatment, with physical and psychological effects that vary in intensity depending on endogenous and exogenous factors (such as, inter alia, length of the mistreatment, age, sex, health, context and vulnerability, etc.), which must be proven in each specific situation. The Court has also specified that any use of force that is not strictly necessary to ensure proper behavior on the part of the detainee constitutes an assault on human dignity, in violation of Article 5 of the American Convention. 199 134. In this case, the lack of an investigation against the alleged perpetrators of the violation of the right to humane treatment [personal integrity] limits the possibility of reaching a conclusion on the allegations of alleged torture committed against Messrs. Montiel and Cabrera. Nevertheless, despite the foregoing, the Court has indicated that, as guarantor of the rights enshrined in the Convention, the State is responsible for ensuring the right to humane treatment of every person 197 United Nations. Economic and Social Council. Report of the Special Rapporteur on Torture, Sir Nigel Rodley. Visit to Mexico UN Doc (E/CNA/1998/38/Add.2), January 14, 1998, para. 43. 198 United Nations. Economic and Social Council. Report of the Special Rapporteur on Torture, supra note 197, para. 64. 199 Cf. Case of Loayza Tamayo v. Peru, supra note 37, para. 57; Case of Miguel Castro-Castro Prison v. Peru. Interpretation of the Judgment on the Merits, Reparations and Costs. Judgment of August 2, 2008. Series C N° 181; para. 76. 52